This invention relates to a disposable pull-on diaper adapted to absorb and hold excretion discharged thereon.
Japanese Patent Application Publication No. 1997-24063A describes a pants-type disposable diaper basically comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between the top- and backsheets, configuring front and rear waist regions opposed to each other and a crotch region extending between these two waist regions so that the front and rear waist regions may be connected to each other to a waist-opening and a pair of leg-openings, wherein elastic members being stretchable in a leg-surrounding direction are attached under tension to peripheral edge portions of the leg-openings, the diaper further comprising a pair of substantially liquid-impervious leak-barrier cuffs (flaps) extending in the leg-surrounding direction in the vicinity of transversely opposite side edges of the core.
In the case of this diaper of prior art, each of the leak-barrier cuffs (flaps) comprising inner and outer sections has a fixed side edge portion, a free side edge portion normally biased to rise on the topsheet and fixed longitudinally opposite end portions collapsed inwardly of the diaper. The respective fixed side edge portions are bonded to the topsheet in the vicinity of transversely opposite side edges of the core and the respective fixed end portions are bonded to the topsheet in the front and rear waist regions. The elastic members being stretchable in the leg-surrounding direction are attached under tension to the respective free side edge portions. In the crotch region, the free side edge portions defining the outer cuffs (flaps) extend inwardly of the core and these free side edge portions are folded back along substantially middle zones thereof outwardly of the core.
The diaper disclosed in the Publication is adapted to be worn in the manner that a wearer inserts his or her legs into the respective leg-openings and then the diaper is pulled up to the wearer""s waist. In the case of this diaper, the elastic members associated with the leg-openings extend along the entire peripheral edge portions of the respective leg-openings and the middle zones of the respective outer cuff (flap) sections along which the free side edge portions are folded back outwardly of the core are not bonded to the diaper and the free side edge portions of the respective outer cuff (flap) sections rising in the crotch region define relatively high barriers. With a disadvantageous consequence, contraction of the elastic members associated with the leg-openings as well as rising of the free side edge portions of the outer cuff (flap) sections reduce the respective leg-openings. As a result, the free side edge portions of the respective outer cuff (flap) sections extending in the crotch region may obstruct the wearer""s legs against being smoothly inserted into the respective leg-openings and make wearing time-consuming operation.
It is an object of this invention to provide a disposable pull-on diaper adapted to be smoothly worn without an anxiety that the free side edge portions of the leak-barrier cuffs might obstruct the wearer""s legs against easily being inserted into the leg-openings.
According to this invention, there is provided a disposable pull-on diaper basically comprising a liquid-pervious topsheet, a liquid-impervious backsheet and a liquid-absorbent core disposed between the top- and backsheets, configuring front and rear waist regions opposed to each other and a crotch region extending between these two waist regions so that the front and rear waist regions may be connected to each other to form a waist-opening and a pair of leg-openings, wherein elastic members being stretchable in a leg-surrounding direction are attached under tension to peripheral edge portions of the leg-openings, the diaper further comprising a pair of substantially liquid-impervious leak-barrier cuffs extending in the leg-surrounding direction in the vicinity of transversely opposite side edges of the core.
According to this invention the elastic members associated with the leg-openings comprise first elastic members extending in the leg-surrounding direction along a front peripheral edge portion of the leg-opening on the side of the front waist region and second elastic members extending in the leg-surrounding direction along a rear peripheral edge portion of the leg-opening on the side of the rear waist region wherein none of the elastic members associated with the leg-openings are present along an intermediate peripheral edge portions extending between the front and rear peripheral edge portions of the leg-opening, the leak-barrier cuffs respectively have fixed side edge portions extending in the leg-surrounding direction in the vicinity of the respective side edge portions of the core, free side edge portions being contiguous to the fixed side edge portions and normally biased to rise on the topsheet and fixed longitudinally opposite end portions collapsed inwardly of the diaper and placed upon the topsheet in the front and rear waist region and, in the crotch region, the free side edge portions extend inward beyond the side edges of the core and are folded back along substantially middle folding lines thereof outward beyond the side edges of the core wherein the free side edge portions are bonded, in the vicinity of the middle folding lines, to the outer surface of the topsheet in the upper zone of the core.
According to one embodiment of this invention, the first elastic members present a stretch stress higher than that of the second elastic members.